Engineering the Climate

The idea of manipulating the Earth's atmosphere has been derided as too risky and too arrogant. That may be changing

The Silver Lining Project that pumps sea water into the sky to create sun-reflecting clouds.

Imagine, if you will, a giant helium balloon, the size of a stadium, floating high above the Earth, and dangling from it is a hose 12 miles long that sprays aerosols into the stratosphere—all with the intent of slowing global warming.

When you’re in the planet-saving business, you need to think big. But big and crazy?

Now massive geoengineering projects—once derided as high-risk lunacy by climate scientists and the height of scientific arrogance by many others—are being taken more seriously these days. According to a survey published last week, about three out of four respondents in the United States, United Kingdom and Canada said they think more research should be done on “solar radiation management,” which would cover things like the sky-hose contraption described above.

Here’s how Jane Long, a scientist and co-chair of the panel behind the report, put it in an interview with Yale Environment 360: “People aren’t doing this because they think, ‘Oh, whoopee! We can change the Earth!’ They’re doing it because they just don’t see any progress and it just seems to be getting worse and they want options on the table.”

Reality check

That’s all well and good, but geoengineering is still pretty much a can of worms with a few snakes mixed in. That big sky-hose project? It’s called Stratospheric Particle Injection Climate Engineering, or SPICE for short, and the British government committed $2.5 million to researching it. There was supposed to be a test run in October with a much smaller model—the hose was slightly more than half a mile long. But it was put on hold for at least six months after 60 organizations from around the world signed a petition arguing more discussion was needed before even testing could begin.

The problem is that geoengineering stirs up a lot of questions beyond “Will this work?” Can you really manipulate nature without ugly ripple effects, such as inadvertent droughts or monsoons? Who decides by how much and where the climate should be cooled—in other words, who controls the thermostat? And what’s to prevent a country from going rogue, even using geoengineering as a weapon?

Jane Long and other scientists acknowledge all that. She says she hopes it never has to be used. But without research and testing, what happens if the worst predictions of climate change come to pass? In her mind, the last thing geoengineering should be is an act of desperation.

Big ideas

Here are some geoengineering ideas out there:

Make like a volcano: Researchers have taken as inspiration the eruption of Mt. Pinatubo in 1991. The sulfur dioxide cloud it generated dropped global temperatures almost a full degree Fahrenheit the following year. That’s the theory behind the giant sky hose—it would pump sulfuric acid aerosol particles into the stratosphere with the goal of reflecting the sun’s radiation. What worries scientists most is the collateral damage that could come with it.

Cloud cover: Then there’s the Silver Lining Project, which would involve developing a fleet of boats designed to pump sea water into the atmosphere, with the intent of creating sun-reflecting clouds. Bill Gates has kicked in money for this idea, but there are questions again about how much it could be controlled.

Space mirrors: Another concept based on reflecting the sun’s rays away from Earth would involve creating a massive “sun shade” of mirrors. But not only would the cost be enormous, some scientists say the rocket launches needed to get the components into space could create so much black soot pollution that it could actually raise the planet’s temperature.

Suck it up: An alternative approach is to forget about the sun and focus instead on getting rid of the excess carbon dioxide in the atmosphere. This could involve building machines that suck it out of the atmosphere. There’s actually potential for a business here (Gates has invested in this one, too), but the cost is still way too high. And there’s the matter of what do you do with all that carbon you capture?

Under the sea: A more “natural” version of carbon removal would involve dumping iron filings into the ocean, which would accelerate the growth of phytoplankton, which, in turn, would ingest more CO2. But it’s not clear how this would affect marine life or if it would even work on the scale needed to make a difference.